01748nas a2200181 4500008004100000245010200041210006900143490000700212520117200219100001101391700001401402700001301416700001701429700001701446700001301463700001801476856007201494 2016 eng d00aA bioreactor with an electro-responsive elastomeric membrane for mimicking intestinal peristalsis0 abioreactor with an electroresponsive elastomeric membrane for mi0 v123 a

This study describes an actuated bioreactor which mimics the pulsatile contractile motion of the intestinal barrier using electro-responsive elastomers as smart materials that undergo deformation upon electrical stimulation. The device consists of an annular dielectric elastomer actuator working as a radial artificial muscle able to rhythmically contract and relax a central cell culture well. The bioreactor maintained up to 4 h of actuation at a frequency of 0.15 Hz and a strain of 8%–10%, to those of the cyclic contraction and relaxation of the small intestine. In vitro tests demonstrated that the device was biocompatible and cell-adhesive for Caco-2 cells, which formed a confluent monolayer following 21 days of culture in the central well. In addition, cellular adhesion and cohesion were maintained after 4 h of continuous cyclic strain. These preliminary results encourage further investigations on the use of dielectric elastomer actuation as a versatile technology that might overcome the limitations of commercially available pneumatic driving systems to obtain bioreactors that can cyclically deform cell cultures in a biomimetic fashion.

1 aCei, D1 aCosta, J.1 aGori, G.1 aFrediani, G.1 aDomenici, C.1 aCarpi, F1 aAhluwalia, A. uhttp://iopscience.iop.org/article/10.1088/1748-3190/12/1/016001/pdf02029nas a2200169 4500008004100000245009900041210006900140300001400209490000700223520143200230100001301662700001701675700001601692700001801708700001701726856011601743 2014 eng d00aEnabling variable-stiffness hand rehabilitation orthoses with dielectric elastomer transducers0 aEnabling variablestiffness hand rehabilitation orthoses with die a205–2110 v363 a

Patients affected by motor disorders of the hand and having residual voluntary movements of fingers or wrist can benefit from self-rehabilitation exercises performed with so-called dynamic hand splints. These systems consist of orthoses equipped with elastic cords or springs, which either provide a sustained stretch or resist voluntary movements of fingers or wrist. These simple systems are limited by the impossibility of modulating the mechanical stiffness. This limitation does not allow for customizations and real-time control of the training exercise, which would improve the rehabilitation efficacy. To overcome this limitation, 'active' orthoses equipped with devices that allow for electrical control of the mechanical stiffness are needed. Here, we report on a solution that relies on compact and light-weight electroactive elastic transducers that replace the passive elastic components. We developed a variable-stiffness transducer made of dielectric elastomers, as the most performing types of electromechanically active polymers. The transducer was manufactured with a silicone film and tested with a purposely-developed stiffness control strategy that allowed for electrical modulations of the force-elongation response. Results showed that the proposed new technology is a promising and viable solution to develop electrically controllable dynamic hand orthoses for hand rehabilitation. ? 2013 IPEM.

1 aCarpi, F1 aFrediani, G.1 aGerboni, C.1 aGemignani, J.1 aDe Rossi, D. uhttp://95.110.227.16/publications/enabling-variable-stiffness-hand-rehabilitation-orthoses-dielectric-elastomer01380nas a2200157 4500008004100000245008000041210006900121490000600190520088800196653001901084100001701103700001501120700001701135700001301152856005701165 2014 eng d00aWearable Wireless Tactile Display for Virtual Interactions with Soft Bodies0 aWearable Wireless Tactile Display for Virtual Interactions with 0 v23 a

We describe here a wearable, wireless, compact, and lightweight tactile display, able to mechanically stimulate the fingertip of users, so as to simulate contact with soft bodies in virtual environments. The device was based on dielectric elastomer actuators, as high-performance electromechanically active polymers. The actuator was arranged at the user’s fingertip, integrated within a plastic case, which also hosted a compact high-voltage circuitry. A custom-made wireless control unit was arranged on the forearm and connected to the display via low-voltage leads. We present the structure of the device and a characterization of it, in terms of electromechanical response and stress relaxation. Furthermore, we present results of a psychophysical test aimed at assessing the ability of the system to generate different levels of force that can be perceived by users.

10aBioengineering1 aFrediani, G.1 aMazzei, D.1 aDe Rossi, D.1 aCarpi, F uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150388/